Quick viewing(Text Mode)

C-044 Sp.Pdf

C-044 Sp.Pdf

1 2 3 4 5 6

DOE RUN PERU LA OROY A DIVISION Doe Run Peru Report to the Minstr of Energy and Mines, 1998

Report to the Ministry of Energy and Mines on PAMA and, request for approval of changes in schedule, December 1998.


Durig its first year of ownership, Doe Run Peru undeltook studies of all of the obligations and developed a plan for meeting those obligations. This report is intended to brief the Mistry on what has been accomplished with regard to the P and Doe Run Peru plan and current schedule of implementation.

There are 16 projects outlined in the PAM which are reviewed here. Because the projects numbers 6, 7, 10, and 11 are an interrelated group of waste issues, we wil review them as a group.

The actual P AM related expenditures incurred by Doe Run Peru for the fiscal year 1998 have been approximately U$3 8 millon compared with US$ 2 7 millon included in the approved PAM

- 1 - Doe Run Peru Report to the Mistr of Energy and Mines, 1998

PAM A Project #1 NEW PLANTS.


This project' s mai objectives are to mitigate the adverse effects of Dioxide (S02) and pariculates contained in the stack gas emissions ftom the Doe Run Peru Metallurgical complex operations, and to comply with emission regulations and air quality guidelines Misterial Resolution No. 315- EM/.estalished by M. , in accordance with Anexo 1 and 3 of TECHNICAL DESCRITION

The original P AM proposes two double contact double absorption sulfuric acid plants in , , and conjunction with substantial process modifications of the products using circuits to fi 89. 35% of the sulfur intake as sulfuric acid or sulfur contained in by- the following , Teniente converter for Cu, Ausmelt for Pb and Lurgi technology for Zo..

The solution proposed by Doe Run Peru is generally the same as the P AMA with some techncal 1998: diferences which are further explained in the Fluor Danel Master Plan Report Sept

One single contact, single absorption Sulfuric Acid plant with separate gas cleaning systems for , maitaining adequate the various smelting operations is preferred because of space requirements gas strength by mig gases, and economies of size and reducing duplication.

The off gases of the oxy-fue1 copper are not considered suitable for sulfric acid recovery at this time.

A new fluid bed copper roaster is proposed along with two larger Pierce Smith converters with Teniente gas tight hoods to achieve adequate sulfr capture in the copper circuit. An EI converter is not considered necessary at this time unless market conditions or concentrates supplies dictate diferently.

It is proposed that gas recirculation in the existing Lead Sinter Plant is the preferred method to upgrade the off gases for treatment in the acid plant. The dross furnace and the lead off gases would continue to be cleaned in the existing cottrell system. This wil result in fixation of 78% ofthe sulfr in the Lead circuit. At this time it is the opinion of Doe Run Peru that smelting of concentrates and secondar lead materials is unproven technology but is deserving of thorough study at a future

- 2- Doe Run Peru Report to the Mistr of Energy and Mines, 1998

study. The date. $0. 5mm has been budgeted for the years 2000 and 2001 for a feasibilty AMA. outcome of this study would directly impact the design of the new acid plants and the P

The stack testing shows particulate emission concentrations wil comply with the R.M. No. 315- 96 Anexos 2 through 5 however a combination of the additional gas cleaning associated with the new sulfuric acid plants and improved cleanng in the existing cottrell syste due to greatly particulate and reduced volumes and dust loading, wil significantly further reduce emissions ftom the plant.


Doe Run Peru commssioned Fluor Daniel to produce a Ten Year Process Master Plan on April 1998, working closely with Doe Run Peru personnel, this report was to include the processing and the Zinc refinery. The Final Report was of SOz gases ftom the Copper, Lead smelters submitted in September, the work relating to the Pama Project 1 consisting of

Establishig primary production goals

Review of proven existing technologies, world wide

Review of operations of the present smelter

Varous metallurgical investigations , and off gases Varous samplig and testing program for metals and impurities,

SOz gases, employing a combination of Establishing a compliant sulfur balance including existing, improved, and new processes

Establishing a cost and budget schedule for the projects

Reporting the findings and reco endations in the 10 year Master plan report


130 932 AF-030- RFS-9101 Master Plan (Amount used by FD) 829 AFE-030- DRP Costs 000 Estimated Costs December 98

- 3 - Doe Run Peru Report to the Ministry of Energy and Mines, 1998

160 761 I Total


The estimated capital cost of the revised solution is US$ 104.6 millon to recover (fix) a total of 502.5 tonnes per day of a projected total of 591.7 tonnes per day of new sulfur intake. Project expenditures would begi in the year 2002 and completion is scheduled for the end of year 2006.

- 4- Doe Run Peru Report to the Mistr of Energy and Mies, 1998



The project objective is to eliminate the emissions to the atmosphere resulting ftom the incomplete distilation of in the coking process. At the time the P AM was approved, the 3 of gases per day cokig cycle was approxiately 18 hours, and emits 23 800 m


In the La Oroya metallurgical complex, metallurgical coke is produced ftom bituminous coal in Curant Knowless furnaces. This coke is used as a fuel in the Lead Smelter sinter plant and blast furnaces.

During the coking process, the coal is subjected to temperatures of approximately 1350 , in a free oxygen environment. The volatile compounds gasifY and are then treated in gas collectors and scrubbers, where, with the help of water, they are cooled and separated ftom the tar. The cleaed gases are then mied with pre-heated air and recycled as fuel to the coking furnace burners.

Due to production increases in the lead smelter, the coke production has been increased to satisfY the feed requirements ofthe sinter plant and blast furnaces by reducing the coking cycle from 24 to 18 hours. This time is insuffcient for the complete combustion of the volatile material contaed in the bitumious coal. Consequently, when the coke is discharged afer an 18 hour coking cycle, there is a signficant emission of these gases to the environment. BACKGROUN

Five alternatives were analyzed in the P AM:

- Operate the furnaces with coking cycles of 24 hours. It is proposed to mitigate the fugitive , and emissions problem by operating the furnaces with coking cycles of 24 to 26 hours overcome the production defecit with imported coke. The anual coal and coke purchasing needs would be:

Purchase 41 000 t of metalurgical cokig coal to produce 27 000 t of coke.

Purchase 8 200 t of metalurgical coke from other coke producers.

- 5 - Doe Run Peru Report to the Mistr of Energy and Mies, 1998

- Installation of ventilation systems (SVEL) The installation of ventilation systems to 3 of the gases emited daily when operating with 20 hour coking capture the 23 800 m cycles would require a major investment in equipment and accessories. The principal problems with this alternative are the high permanent maintenace cost of the equipment and the limited space avaiable in the coke plant.

- Substitute totaly the purchase of coal with metallurgical coke. - Encourage a coke producer to locate near La Oroya.

- Build a state of the art coke plant (totally enclosed vertical design) without by-products recuperation.

AB a result of the evaluations, a decision was made to pursue the first alternative, to operate 24 hour cycles and to purchase 8 200 tonnes of metallurgical coke per year.


Since May 24 1998, a total of 8 800 tonnes of metallurgical coke has been imported. Of the total st of October 5% was coke consumed through the 31 , 1998, 20 5% was imported and 79 produced ftom coal imported from Bradford U.

Increasing the coking cycle time (to an average of 22 hours) has improved the coke quality. The fixed has increased ftom 86 7% to 88 , the net coke recovery has increased from 9% to 68 7% and the gross coke recovery has increased from 79 7% to 83 1%. Additionally, gas emissions to the environment have been reduced substantially to 6 100 m / day. th of AB can be appreciated, since the project was implemented on the 24 May 1998 approxiately 59% of the cokig cycles were extended to 22 hours. Cycles of 23 and 24 hours wil be developed progressively, in such way that it does not affect the production oflead bullon.

The purchase of a 10 000 m.1. lot of metallurgical coke is foreseen for 1999. It is expected to arve in January 1999.


lead The expenses for the coke purchase are being charged to the operating account of the smelter.

- 6- Doe Run Peru Report to the Mistry of Energy and Mies, 1998


The origial P AM did not include the investment required for this project.


th 1998. It is estimated that by January 1999 The 22 hour coking cycle was initiated on May 24 100% of the coke production wil be obtained using a 24 hour coking cycle and fugitive gas emissions wil be elimnated.

7 - Doe Run Peru Report to the Miistry of Energy and Mines, 1998



The project objectives are the reduction of N 6 fuel oil consumption in the Anodic Residue plant through the use of oxygen enrched air for combustion, and the elimination of nitrogen (NOx) gas generated by the use of the oxidizing reagent sodium nitrate in the last stage of the process.


The Anodic Residue plant treats the anode slimes ftom the Copper and Lead Refineries which constitutes the for the recovery of dore, , , selenium, and tellurium. The anode slimes are processed in succesive stages to remove the impurities: fusion, conversion and fially cupellation to obtain dore. CupeUation is a batch process with a duration of approximately 7 days. The final stage is the "washing" of dore by intense oxidation with sodium nitrate for about 24 hours during which NO gases are generated

some The oxidant is the oxygen liberated when sodium nitrate is reduced to present permts a longer action of this oxygen and aids in the removal of impurities from the dore metal. BACKGROUN

Two alternative were analyzed in the P

- The use of oxygen gas in the fusion, conversion and cupellation processes. The process consists of two stages: enrch die combustion air in the fusion and conversion processes reducing the consumption of fuel, improving the processes' effciencies , and reducing the volume of off-gases, and replace the use of sodium nitrate in the cupellation process with oxygen gas injected into the metalc bath with a lance or special burner with the intent that the generation of NOx would be elinated. - Replacement of 3 cupels by the Bottom Blown Oxygen Cupel (BBOC). Technology which consists of oxygen injection through the bottom of the metal bath thereby assurig the introduction of oxygen directly into the reaction zone. High reaction rates and improved effciencies are achieved, resulting in reduced fuel consumption and reduced emissions.

- 8- Doe Run Peru Report to the Mistr of Energy and Mies, 1998

Afer the evaluating the alternatives, the use of oxygen gas in the fusion, conversion and cupellation processes was selected.


In a fist phase, staring 19th December, 1996 the use of oxygen gas to enrich the combustion air to 26 - 28% oxygen for the fusion process was implemented. It was found that the process was improved by achieving higher temperatures, reducing fuel consumption by 86 kg per tonne treated slimes, and reducing the volume of off gas by 30% which improved the recovery of gases and dust. st December 1996 In a second phase, staring 21 , the use of oxygen to enrch the air injected into the metalc bath through the blowers in the conversion and cupellation processes was implemented. The impurities such as , antimony, copper, bismuth, selenium, and tellurium that accompany the in stages of conversion and cupellation are oxidized and removed progressively. The use of pure oxygen enrchment alone is effcient for the elimination of bismuth in the cupeUation process, but is ineffcient for oxidizing selenium and tellurium. These elements require the action of a strong oxidant like sodium nitrate to form a sodium oxide , rich in selenium and tellurium. The objective of eliminating the consumption of sodium nitrate could not be achieved, only a reduction of 26 kg of sodium nitrate per tonne of dore was achieved accompaned by a slight reduction of the NOX gas emissions.

The result is that the process wil continue to utilze the 1st. phase changes and the resulting improvement in gas reduction, also for the second phase, selenium and telurium sulfatation wil be included, which would reduce sodium nitrate consumption, therefore the NO gas emissions. Ths projec is considered closed.


The expenses related to this project estimated in US $ 391 000 were charges to the Anodic Residue plant operating account.


The original P AM did not include the investment required for this project.


Phase I - Use of oxygen gas to enrich the combustion air: 1996 - 1997 / Complete and Continuing

- 9- Doe Run Peru Report to the Mistr of Energy and Mies, 1998

Phase n - Use of oxygen gas in the cupellation process: 1996 - 1997 / Discontinued

- 10- Doe Run Peru Report to the Mistr of Energy and Mies, 1998



Currently, the acidic ferrous solution arising ftom the copper sulfate mother liquid solution cementation stage in the Copper Refinery is discharged to the river Yauli. The objective of this project is to treat this solution to obtain a neutralized solution suitable for and/or dischargig, prior to recovering the and puriying the raffate solution to obtain a final effuent with impurity contents below the maxmum permssible limts established by the MEM ( R.M. No. 011-96-EMN). DESCRITION

To control the impurity levels in the Copper Refiery electrolyte, 30 to 40 thousand liters (Bleed Off are removed ftom the circuit daily. This bleed is transferred to neutralizers and heated with steam. Electrolytic copper and copper oxide is then added. Next, a saturated solution of copper sulfate is produced following air oxidation and evaporation. Copper sulfate crystals. are produced ftom the saturated solution by. vacuum crystallzation.

The CUS04 crystals are separated in a centrige and the remaining mother liquid is partially recirculated to the neutralizers. The excess mother liquid is transferred to a precipitation tank and heated with steam. Scrap is added to precipitate copper in a cement fonn for recycling to the smelter. The copper ftee acidic ferrous solution (16 000 Vday), is finally discharged to the Yauli nver. BACKGROUN

Three alternatives were evaluated in the P AMA:

1. Oxidation Process - Neutralization 2. process by stages 3. Predilution - SX/W - neutralition process

Afer evaluating the alternatives, No. , Predilution, solvent extraction with electro-winning and neutralization of the fial eftuent was selected. The established parameters were as follows:

- 11 - Doe Run Peru Report to the Mistr of Energy and Mies, 1998

Predilution: pH: 1 23 and Cu: 3 2 g/I. SX-EW : pH: 1 23; Cu: 3 20 g/ and reagent Acorga: M5615. Stage 1 Neutralization: pH 3 and Cu: 0 11 g/I. Stage n Neutralation: pH 7 and Cu: 0 01 mg/.

Estimated Capital investment : U.S. $ 500000. Initial Execution Schedule : 1 at Quarter of 1997. 1998 Approved Amendment : 4 . Quarter of2006 ACTUAL SITUATION

Fluor Daniel was hired by Doe Run Peru for project evaluation and development. They took over this project and after reviewing the requirement, changed the name to "Refinery Bleed" with- project implementation in two phases. Phase I, comprised of the analysis and evaluation of six possible alternatives, including capital investment and operating cost estimates.

Fluor Daniel, DRP's Project Group, the Deparment of Metallurgical Investigations and the Copper and Lead Refieries operating personnel, decided on the treatment of the Bleed Off (60. 5 m /day), instead of the fial solution ftom the mother liquid (16 /day). The decision to discontinue copper sulfate production is conditional to market conditions.

The selected Bleed Off scheme was as follows: a) The bleed off solution, estimated at 60. 5 m /day after allowing for future expansions of the copper refiery, together with a volume of 240 m /day of cooling and process water, wil be treated in a first stage neutralization with milk of to reach pH 2.0. This wil neutralize some of the sulfric acid present in the mi and precipitate gypsum. After settling and fitration, the gypsum wil be recyled to the copper smelter for further treatment. It should be understood that for dilution purposes, the 240m /day of cooling and process water includes the total volume of process which exceed the maxmum permssible levels of impurities, and additional coolig and process water which has impurities below the permssible levels. b) The fist neutralation stage overfow goes to a second neutralization stage with the addition of ferrc chloride and milk of lime until a pH of 10. 0 is reached. This precipitates hydroxides such as Copper, Lead, Arsenic, and Zinc, and parially precipitates Bismuth and Antimony. The residue produced afer settling and fiterig wil be sent to the Copper Smelter for treatment. c) Sulfric acid is added to the second neutralization overfow in order to adjust the pH to 9. Afer fitration, this solution is discharged to Yauli river.

The partial precipitation of Bismuth and Antimony during the second neutralization stage ensures that the impurities are below the maxmum permssible levels.

- 12- Doe Run Peru Report to the Ministry of Energy and Mines, 1998

The estimated capital investment for the neutralization plant is US $ 5. 8 millon, and the estimated operating cost is US $ 2.6 millon per year.

Paralel to the above, Sverdrup Civil Inc. company completed a feasibilty study for the Central Industrial Wase Water Treatment Plant, located in the area of the Copper and Lead Smelters. This will process all the industrial effuents ftom all the plants in the area, including the slag granulation water ( blow down), acidic waters ftom future Sulfuric Acid Plants, , cooling waters and storm water. The total capital investment for this plant in estimated at US $ 32 millon, and the operating cost is estimated at US 3 6 millon per year.

In these circumstances, the following alternatives were evaluated: a) Operate the Copper Refinery ''Refinery Bleed" Neutralization Plant in parallel with the Central Industrial Waste Water Treatment Plant in the smelter area, including the industrial effuents ftom the Lead and Copper refineries. b) Operate only the Central Industrial Waste Water Treatment Plant in the smelter area, including the industrial eftuents from the Lead and Copper refineries.

Recent project analysis has concluded that an electro winnng treatment of the wasted electrolyte in Liberator Cells would reduce the copper content in the wasted electrolyte to 5 g/, without producing Arsine gas. This would recover 90% of the copper in the wasted electrolyte (2 25 t of Copper /day ). The stripped solution would then be sent to a hea tank to be pumped, together with other process solutions, not exceeding 100 m3/day, to the equalization basin of the Central Industrial Waste Water Treatment Plant located in the south end of the smelter area. Here they would be treated , along with other industrial effuents from the Copper and Lead smelters, Zinc refiery coolig waters, and effuents ftom the acid plant.

From the evaluation of the two above mentioned alternatives, it was concluded that economically and operationally, alternative b) was more appropriate. That is to operate only the Central Industrial Waste Water Treatment Plant in the smelter area and include the effuents ftom the Copper refier.

In conclusion the origial objective included in the P AM approved by MEM, is being changed as described in the above.


- 13 - Doe Run Peru Report to the Ministry of Energy and Mies, 1998

AF-028- RFS-4002 Phase n - Detail Engineering 813 478

AF-050- RFS-4003 Procurement & Construction 101

Estimated Costs December 98 225 000

347 607


The estimated capital cost of the revised solution is US $4. 5 millon to send the liquid from the refiery to the smelter and treat it in the new IW. Project expenditures would begin in the year 2005 and completion is scheduled for the end of year 2006.

- 14 - Doe Run Peru Report to the Minstry of Energy and Mies, 1998




This group of projects has the principal objective of eliminating the discharge of contamnated process liquid effuents and cooling water into the Mantaro River to comply with the Mistry Regulations on maxum allowable discharges included in the R.M.No.011-96-EM/.

Project No. 6 is concerned with segregating and collecting Smelter cooling water flows and recycling by gravity to the Mantero River water pumps. The desired effect was to reduce the volume of contamated mixed effuents by separating out the cooling water and to improve the quantity and quality of the Mantero water system. The cost estimation in the P AMA was US$ 350 for this projec.

Project No. 7 deals with a selected effuent ftom the Silver Refinery which is a higWy acidic solution ftom the mud parting process that has been relieved of metal values by cementation before releasing to the river. The P AM proposes to reuse the sulfuric acid solution in the Zinc Plant Leachig Circuit. US$5000 was estimated for this project later. Difculties in the impurity control durig the leachig process were found, and the option was cancelled.

Project No. 10 also deals with a specific waste stream, Lead Plant speiss granulation water. The PAM alows US$55 OOO for complete recycling ofthis water.

Project No. 11 is a process improvement equipment installation, Zinc Plant anode cleaning solid and liquid effuents. wherein consideration has been given to recycling the manganese oxide obtaied in the zinc process and treating liquid effuents in the central Industrial Waste Water treatment plant. The project was slated for one year to complete at a cost ofUS$15 OOO.

- 15 - Doe Run Peru Report to the Miistr of Energy and Mies, 1998


The origial P AM solution attempted to deal with the major process effuents of the facilty by recirculation or retreatment. It has since become apparent to Doe Run Peru operations that the waste streams of the P AM Projects 6 , 10, and 11 have adverse effects on the metallurgical balance of the plant and are best left to be treated as a process blowdown in the CWWP which is discussed in detai under Project No.

The Project NO. 6 has been deferred by the current plan of collecting and treating the non- contact cooling water separately, also discussed under Project NO.


These effuent flows were considered as part of the total flow of the central Industrial Waste Water treatment plant during PAM project No. 8 feasibilty study.


The costs incurred by Doe Run Peru for these projects has been included in the costs shown for Project No.


The schedule of work and costs for this group of projects is included in the revised plan for AM Project No.

- 16 - Doe Run Peru Report to the Ministry of Energy and Mies, 1998



Ths project has the principal objective of eliminating the discharge of contaminated liquid effuents into the MantaTO River to comply with the Ministry Regulations on maximum allowable discharges included in the RM.No.011-96-EMI. Project No. 8 is the principal project regarding liquid effuents from the La Oroya Complex and deals with treatment of al liquid effuents ftom the facility including Process effuents, cooling water effuents, sewage, wash water effuents, and storm water runoff The P AM solution is a two stage neutralation and clarification process to treat 9. 1 m /min of combined sewage and process effuents. The sludge produced was to be pumped to a lined pond located further downstream of the smelter. Storm water runoff was to be cared by the existing canals to sedimentation ponds near the Plant. Cooling waters were to be recirculated to the power house


The original P AM solution attempted to deal with the liquid effuents of the facility in a reasonable maner, however, it became apparent to Doe Run Peru that the planning for the management of the cooling water and wastewaters at the smelter required more detaied attention. It was not felt that the plan was adequate to deal with the impacts outlined in the EV AP or possibly to comply with the MEM efiuent standards. As a result, Doe Run Peru undertook a major study of the systems to control the wastewater contamination ftom the plant. This study was conducted by Sverdrup Corporation of St. Louis, Missouri with the input and collaboration of Doe Run Peru La Oroya personnel and Fluor Danel.


The study was concluded with a series of eight (8) reports and one addendum report. The Final Report Task NO. 8 - Master Plan Report Industrial Wastewater Treatment Master Plan and Preli Engieerig was issued by Sverdrup in November, 1998

The preliminar tasks ( and reports) consisted of the following: 1.- Data collection

- 17 - Doe Run Penl Report to the Ministr of Energy and Mines, 1998

- Experimental Process confrmation and addendum, Pilot Testing - Process Confrmation - Main WWTP - Process Confrmation - Pretreatment of Special Streams - Wasewater Collection Systems - Study of Alternative Site Locations - Sludge Handling and Disposal The Final Report includes summary discussions as well as capital and operating cost, and project schedules.

The study was conducted concurrently with and takes into account an extensive effort by Doe Run Peru and Fluor Danel to formulate a ten year process master plan for the facilty. Because of this and other considerations, the recommendations of the study are different than the P AM. The pricipal points are summaried here:

The Central Waste Water Treatment Plant (CWWTP) wil be located at the lower end of the Smelter in the area of the Indium Plant. The CWWP plant is designed to treat a reduced volume of8. /min and wil be a conventional lime (CaO) neutralization process, consisting of pre-neutraliztion and oxidation reactor tanks, clarication, and final pH adjustment. Sludge solids formed are removed as parialy dried fiter cake for reprocessing in the smelter. Small scale pilot plant testing indicated that fitration of the effuent ftom the solid liquid separation is not required for compliance with Anex 1 and Class III stream quality standards.

The highy acidic Sulfric Acid Plant blowdown wil be pre-neutralzed, producing a large quantity of gypsum solids; the liquor wil be treated for removal as mied with the process effuents.

The Plant cooling water system effuent requires only settling to remove suspended solids to meet effuent requirements. The study proposes to collect cooling water, settle, remove sludges for recycle or storage, and to release the clarfied effuent to the Mantero River. Recycling of individual cooling water streams wil be studied and implemented as appropriate over time. Recirculation of the clarfied water as per P AM Project # 6 would have to be proven to be economicaly viable in order to be implemented.

The Plant storm water runoff was determed to be contamnated with solids and dissolved heavy metals and requires treatment before release. The proposed scheme is to collect runoff ftom the 41 hectare area of the Smelter to an equalization tank where the solids are settled out for later handling and the liquid is metered into the neutralzation plant along with the process effuents.

The santar sewage effuent from the facilties within the Smelter are collected separately and conveyed to a municipal sewage treatment plant along with residential sewage from the Doe Run Peru community. The mai intent is to prevent the health and sanitary risk of commngling industrial sludges with sanitary sludges. Also the combined character of the flows may interfere with adequate treatment.

- 18 - Doe Run Peru Report to the Mistr of Energy and Mies, 1998

The eftuents ftom projects No.'s 6 10 & 11 have been included.

The solids recvered ITom settling the cooling water and storm water wil be fitered in the CWW facilty, analyzed and either recycled to the Smelter or disposed of in a secure landfill.

Al process eftuents wil be evaluated for economics and techncal feasibilty.


AF-019- RFS-3801 Industrial Waste Water Study $134 636

AFE-002- Feasibilty Study $502 862

Estimated Costs December 98 $22 000

Total $659 498


The estimated capital cost of the revised solution is over US$30 millon. As a result of the greater complexity and desirabilty to phase the implementation, a six year plan to implement the study has been developed and project completion is scheduled for the end of calendar year 2004 additional time for the implementation of this project is required due to the increased size of the project.

The implementation schedule consists of six phases as follows: 1.- Wastewater Collection Systems - Cooling Water Treatment 3. - Equaltion Basin - CIWWP - Chemical Feed Systems - Sludge Handling System

The basic engineering design of the waste water collection systems was started in November 1998 with budget ofUS$1.5 milion.

A phase 2 to enlarge the cooling water treatment system may follow and is included in the capital cost estimate. Further, room is allowed in the design for final eftuent fitration and additional reactor stages if required in the future. No cost for this consideration is included.

- 19- Doe Run Peru Report to the Ministr of Energy and Mies, 1998

The cost for construction of a hazardous waste landfill and transport equipment wil be included when the chaacteristics of the sludge solids that wil be produced are better defined and are deferred for a separate study. The preliary plan is to store them at Cochabamba.

- 20- Doe Run Peru Report to the Mistr of Energy and Mies, 1998



The project objective is to eliminate the drainage to the Mantaro River of the contamnated solutions contaied in the lead muds stored adjacent to the Hydro- unit of the Zileret Plant. DESCRITION

In the Hydro-metallurgy Unit of the Zinc Leached Residue Plant, a lead containing leached residue (mud) is stored adjacent to the Plant prior to recycling to the Lead Smelter. Whle it is in the storage area, there is drainage of the solution contained in the mud to channel No. 136 which discharges to the Mantaro River. This effuent significantly increases the contaminants in the chanel.

The proposed solution is to design and construct a retention wall in the Lead mud storage area with a draiage and collection system to recirculate the solutions back to the plant. Storm waters that contact the mud would be isolated as well.

Investment amount: U. S. $ 5 000.


The retainig wal and the solution diversion channel construction work was completed the 20 of Mach, 1998.

The acid solution draied ftom die lead mud storage area is chaneled to a sump where an existing Galigher pump recirculates the solution to the wash water tans for reuse in the acid leaching processes of the Hydro-metallurgy Unit. With this, the lead mud solution contamnant drainage to the channels that discharge to the Mantaro River was elimiated. This project is concluded.


1l April Expense registered by accounting through 30 , 1998 - U.S. $ 3 856

- 21 - , y

Doe Run Peru Report to the Ministr of Energy and Mines, 1998



This project has the objective of eliminating the partial discharge of copper and lead slag, and slag granulation water into the Mantaro River to comply with the Ministry Regulations on the disposa of solid and liquid emissions included in theR.M.no.01l-96-EMI. TECHNICAL DESCRITION

Rotar drum de-watering devices were proposed to produce a de-watered slag product which was then transported by conveyor belt to an intermediate storage site on the left side of the Mantaro river. From there, the slag was to be trucked to Huanchan for final storage.

The current proposal by Doe Run Peru retains a closed circuit granulation system, employing reduced volumes of granulation water, wil elinate solid and liquid emissions to the Mantaro River. An alternative but well proven design is proposed for the slag dewatering duty. The existing cable car system wil be upgraded to modern design standards to transport the slag to Huanchan where the slag wi be distributed with the existing conveyor belt systems. An improved intermediate storage bin arangement is also proposed for the de-watered slag, ahead of the cable car loading station.


Doe Run Peru initiated a world wide review of copper and lead smelter slag handling procedures. A study team of Doe Run, Doe Run Peru, and Fluor Daniel specialists travelled extensively, evaluating several hundred options over a period of seven months. Three potential storage sites were considered.

The team conclusions and recommendations were presented in report, R.F. S. 3001 SLAG MANAGEMENT PREFEASIDILITY REPORT P. A.M. A. PROJECT #12 in September 1998.

Some rejected options were detailed in report RF. S. 3001 SLAG MAAGEMENT REJECTED OPTIONS REPORT P.A.M.A. PROJECT #12 in October 1998.

In paralel with the study team work, Knght Piesold Consultores was commssioned by Doe Run Peru to perform a conceptual design of a number of smelter slag dump confgurations at three locations and consider Ferrtes and domestic trash management. The Final Report, Disefio Conceptual de Alternativas para los Depositos de Escorias de Cobre y Plomo, Ferritas de Zinc

- 22- Doe Run Peru Report to the Ministry of Energy and Mines, 1998

Basura Domestica, June 1998, indicated a satisfactory remaining useful life at the Huanchan site. This work was then followed closely by an evaluation of previous site stability studies, a new geotechnca field evaluation (Drillng and trenching) of the sites, and a flaw analysis study also by Knght Piesold.


AFE-021- RFS-3001 Slag Handling Study 555 459

AF-004- Feasibility Study 132 544

Estimated Costs December 98 000

Total 723 003


The estimated capital cost of the revised solution is US$ 6. 9 millon. Project completion scheduled for the end of caendar yea 2001.

- 23- Doe Run Peru Rep011 to the Mistr of Energy and Mines, 1998



The project objective is to evaluate the stabilty and overall condition of the slag deposits, to estalish the work required to mitigate or elimnate the environmental impact, and to determe the remediation work required for closure.

Also to be considered is the work corresponding to the implementation of a new deposit which respecs the environment guidelines issued by MEM.


In the 1996 PAM Project #13, the determation was made to abandon the Huanchan area according to recommendations ftom the geotechncal studies regarding physical stabilty of the deposits and their future slag storage capacity. The maximum height of the deposits was dermed at 3 762 m. s.l., with a slope of 1.5H to 1.9Vand a conical projection not supported in the side , estimating a useful storage lie beteen 10 and 13 years.

Additionaly the construction of a collection channel was recommended to control storm water ftom the hills and avoid percolation to the deposit.

The new slag deposit would be located in Cochabamba.

A plan would be executed for the closure and abandonment that would ensure the physical and seismic stailty of the deposits, and the area.

Durig the existing deposit's remainig life, the new deposit at Cochabamba would be prepared to assure the continuity of operations and slag deposition.

Table 1: P AM Project , 1996 Estimated Costs Amount (US$ Description mion)

- 24- Doe Run Peru Report to the Mistry of Energy and Mies, 1998


It is important to highlight that PAM Project N' 13 , 1996 was developed based on varous studies performed by Rescan Peru, which are detaied in Table NO.

Table M' 2: Base Studies PAM December 1996

Doc. Title of Document Author and No. Date of Emission Plan de Cierre del Deposito de Escorias de Cobre y Plomo de la Rescan Peru - Fundicion de La Oroya - ESTUIO DE FACTffILIDAD - ANXOS Diciembre - Plan de Cierre de los Depositos de Ferrtas y Escorias - La Oroya - 1996 Investigaciones Basicas - V olumen 1: Estudio Geologico Investigaciones Geotecnicas. Rescan Peru. December 1996 Plan de Cierre del Deposito de Escorias de Cobre y Plomo de la Rescan Peru Fundicion de La Oroya - ESTUDIO DE F ACTffILIDAD - ANXOS - Diciembre Plan de Cierre de los Depositos de Ferrtas y Escorias - La Oroya - 1996 Investigaciones Basicas - V olumen 2: Estudio de Riesgo Sismico Rescan Peru, December 1996 Plan de Cierre del Deposito de Escorias de Cobre y Plomo de la Rescan Peru Fundicion de La Oroya - ESTUIO DE F ACTffILIDAD - ANXOS Diciembre - Plan de Cierre de los Depositos de Ferritas y Escorias - La Oroya - 1996 Investigaciones Basicas - V olumen 3: Balance Hidrologico, Rescan Peru, December 1996 Plan de Cierre del Deposito de Escorias de Cobre y Plomo de la Rescan Peru Fundicion de La Oroya - ESTUDIO DE F ACTffILIDAD - ANXOS Diciembre - Plan de Cierre de los Depositos de Ferrtas y Escorias - La Oroya - 1996 Investigaciones Basicas - Volumen 4: Diagnostico y Tratamiento de E1:uentes, Rescan Peru, December 1996 Plan de Cierre del Deposito de Escorias de Cobre y Plomo de la Rescan Peru Fundicion de La Oroya - ESTUDIO DE F ACTffILIDAD - ANXOS Diciembre - Plan de Cierre de los Depositos de Ferritas y Escorias - La Oroya 1996 Investigaciones Basicas - V olumen 5: Analisis de Estabildad - Deposito de Escorias, Rescan Peru, December 1996 Plan de Cierre del Deposito de Escorias de Cobre y Plomo de la Rescan Peru Fundicion de La Oroya - Ingenieria Basica, Rescan Per, December Diciembre 1996 1996

- 25- Doe Run Peru Report to the Mistr of Energy and Mies, 1998

The transfer contract of La Oroya ftom Centromin of Metaloroya now Doe Run Peru on August , 1997 provided for Doe Run Peru to utilize Huanchan for up to 3 years.

According to the P AM, Centromin retained the responsibility for closing Huanchan in case DRP decides to abandon Huanchan as a slag depost alternative. If MEM approves the continued use of Huanchan as proposed, and Centromin and Doe Run negotiate the transfer of the site then Doe run would probably accept responsibilty for the closure as part of the agreement.


In the following sections the modified PAM Project , ftom Doe Run Peru is described. Ths revised project is intended to improve on and replace the PAM Project , 1996.

The modified project recommends to continue using Huanchan as the slag deposit due to the new staility study results and the long storage life because of the revised design.

The modified Project 13 has the following objectives:

Evaluate the stabilty of a new expanded deposit confguration both during the operation period, and afer closure.

Determe the required work to prepare the Huanchan area for the continuous deposition of slag in the future.

Determne the work required to close and abandon (remediate) the deposit during and afer the active period of slag deposition.

The slag deposit is located in an aluvial terrace in the left margin of the Mantaro river, at a 2km distance ( by highway) ftom the smelter area, in the zone called Huanchan. The slag wil be transported using the existing cable car system, modernzed and improved as necessar. The slag wil be distributed on the Huanchan site using conveyor belts, respecting a general slope of 5H: 1 V. The deposit has been designed to comply with the physical stabilty requirements durig operation and closure stages. It is estimated that using the confguration included in the drawing L3103MA-ClOO, there are approximately 70 more years remaining of slag storage capacity.

The main features of the design in the study recommends, include:

(See also Dwgs. ClOO, C200, and tale No.

Maxum nomial height of 200m, or elevation 3915m. s.1, support the deposit in the hillside.

General slopes of 2.5H: 1 V

- 26- Doe Run Peru Report to the Miistr of Energy and Mies, 1998

The deposit wil be built in approximately 10m high banks with intermediate slopes of 1.5H:1V

For each 10m high ban there wil be a 10 m wide area, which results in an overall slope of 2. 5H: 1 V (see Detai 2 in drawing N' L31 03MA-C200)

As the banks are completed the reclamation process wil commence, leaving a uniform 2. 5H: 1 V slope.

A 20m. separation area wil be left between the slope limit and the central highway.

A 3m. berm wil be built at the toe of the slag deposit. Topsoil wil be placed over this berm to faciltate revegetation.

A draiage system wil be installed under the toe of the dump to collect water infitration ftom the deposit.

Alternatives for the zinc ferrites dumps are to be relocated to a new deposit or reprocessing them, freeing this area for future slag deposits.

Surface tUnoff flow control employing oversized diverting channels has been included to divert the surace flow water and avoid it' s flow into the deposit. The chanels wil be of suffcient size that they can be cleaned with heavy equipment. See Detail 3, Drawing N' L3103MA-C200.

The deposit wil be reclaimed as the slope bans are completed. During the first 5 to 10 yeas, Doe Run Peru wil experiment with varous types of vegetation, in order to fid suitable types for revegetation. The reclaim work will star at year 10. The overall slope of 2. 5H: 1 V wil faciltate equipment access during all phases of remediation.

The study recommended a drillng program which results would be incorporated into the stabilty and geotechncal studies.

The design was developed in a series of studies performed by Knght Piesold Consultores S. as detaied in Table No. 5. The following techncal aspects ofthe slag deposit were considered: Geotechncal Investigations with the purpose of 1) Establish the geological background of the area; 2) Evaluate the stabilty condition of the type of soils that currently exist in the site (including assays to determne the cut resistance parameters for each type of soil; Evaluate the soil conditions for building the proposed work; Identif and quantif the potential material borrow sites for construction.

- 27- Doe Run Peru Report to the Mistr of Energy and Mies, 1998

Slope stabilty analysis: Evaluation of the 2. 5H: 1 V slope was performed, under static a pseudo static conditions. Three critical sections were analysed, and as shown in figures N' 1 and 2, the results indicate that facor are well over the mium required enrig stailty.

Table N' 3: Safety factors for physical stability of the Huanchan slag deposits.

Section Maximum Deposit Minimum safety Minimum safety Nominal maximum factor under static factor under pseudo Height height level conditions static conditions (meters) (m. (lOin = 1. (min = 1.3) 200 3915 1.49 200 3915 1.57 200 3915 1.44 It is important to highlight that the limitation of maximum height for the deposit had been determned assuming that the slags wil continue to be stored with a slope of 1.5H: 1 V. The present design proposes to reduce the slope to 2.5H: 1 V, therefore the stabilty analysis indicate a greater safety factor than that required by the Ministry of Energy and Mines (according to the Guia Ambiental para la Estabildad de Taludes de Depositos de Residuos Solidos Provenientes de Actividades Mieras

Table No.4, Main diferences between PAM Project No 13, 1996 and the PAM project N 1998

Issue 1998 PAM 1996 PAM Maxmum height of the 200 meters 70 meters de osit. Slope Deposition 5H: 1 V, improved safety 5H: IV (aprox. factors of desi n Distance ftom the slag slope 20 meters The slope bottom is adjacent to base to the Central hi the hi wa in some areas. Deposit Area Includes the area curently used Does not include the area for Zinc ferrites ponds No.'s 3 currently used for Zinc ferrites and 4 onds No. s 3 and 4 Intration control in the Berm at the deposit bottom Only a trench at the bottom of slag deposit perforated collection pipe in the the slag deposit. slags and in a trench outside the ber. Future Ca acit roxiatel 70 ears From 10 ton ears New Deposit The Huanchan is adequate to In Cochabamba receive additional sla

- 28- Doe Run Peru Report to the Mistr of Energy and Mies, 1998

Diverting Chanels Wil capture more than 45 lis. Capture a maxmum flow of 45

Could be cleaned with mobile lis. Must be to cleaned by equipment. hand.

Related Studies Performed during 1998

Following is a detail of the studies performed by Knight Piesold during 1998, related to the slag deposit design in Huanchan.

Table 5: Studies Completed in 1998 Title of the Document Author and issue date Conceptual Design of Alternatives for Deposits of Copper Slags, Lead Knght Piesold, June Slags, Zinc Ferrtes, and Municipal Solid Wastes 1998 Revew of Existing Geotechnical and Related Information for Huanchan Knght Piesold and Cochabamba November, 1998 Investigaciones Geotecnicas de Huanchim, Cochabamba y el Area No Knght Piesold December, 1998


278 236

Tota 278 236


The estimated cost of the required work to adequate the Huanchan area is US$3. 9. (This cost does not include the Zinc Ferrtes relocation work.)

Project is scheduled to be completed by the end of year 2003.

- 29- Doe Run Peru Report to the Ministry of Energy and Mies, 1998



This three phased project seeks to mitigate environmental pollution resulting ftom the arsenic trioxide deposits accumulated by the La Oroya Metallurgical complex at Malpaso and Vado, and to construct a new deposit at Vado (for current production). The deposits would be constructed according to the standards identified in the original P AM. Doe Run Peru under the transfer. agreement with Centromi, can use the Vado landfill through August of2000.


Whle the Project No. 14 closure projects are the responsibilty ofCentromin, the new deposit at Vado is the responsibilty of Doe Run Peru. We wil only discuss the activity relating to the new landfill.


Two approaches were taken during the past year. The fist was to design the new landfill at Vado and defie the method of transport and deposition. The revision to the original design performed by ADI was undertaken by Bar Engineering Company of Minneapolis, Minnesota and the operational aspects were studied by a tea of Doe Run Peru operators in co unction with Fluor Danel. The groups worked together to produce the safest optimum solution possible. The plan view and elevations of the landfill design are attached. The arsenic trioxide as produced is a bone dry dust. The current recommendation is that the dry material is placed in a "torpedo type" rail car at the smelter and transported to Vado via the existing rail system. At the site, a . mi of arsenic trioxide, cement, lime, and water wil be produced and the slurry wil be deposited into the double lined landfill. Recent laboratory testing indicates that the mix wil set up within 24 hours. In this condition, the material is more resistant to releaching, dusting, and other losses and reduces the impact of the uncovered storage while the dump is being filled.

Optimtion of the slurr mi and the handling system has continued.

This landfil plan wil be brought forward through the Environmental Impact Assessment process to obtain a permit for construction in the year 2000.

- 30- Doe Run Peru Report to the Mistry of Energy and Mies, 1998


AF-020- RFS-4101 Arsenic Trioxide Handling 107

AFE-003- Engineering Study 424

Estimated Costs December 98 000

Total 531


The estimated capital cost for the intial confguration of the new Vado Landfill system is estimated at US$1.9 milion and another US $1.9 mion to get to fial confguration. The project would require seven months to complete the initial confguration afer approval to proced is received and the necessar permts are in place, estimated to be completed by the end of yea 2000.

The cost of this project are heavily dependent on the availabilty of suitable materials such as clay, drainage materials, topsoil, etc. Sources have been identified that are suitable under the right conditions, and alternatives continue to be searched for.

- 31 - Doe Run Peru Report to the Minstr of Energy and Mies, 1998



This project has two objectives. First, to close and abandon the existing ferrtes deposits at Huanchan and second, to evaluate methods of recovering the metal values from the ferrite deposits.

Centromin retains responsibilty for stabilzation and closure of the ferrite deposits. However under the terms of the transfer agreement for La Oroya between Centromin and Doe Run Peru Doe Run Peru has an option to retain the ferrites for reprocessing. This option can be exercised- assume withi three yeas or before August, 2000. If exercised, then Doe Run Peru would responsibilties for closure or relocation of the deposits.

The original P AM only includes a budget for the abandonment, DRP is currently investigating the option to reprocess the ferrtes.


Doe Run Peru concurs with the approach outlined in P AM # 15.


examined Doe Run Peru has constructed a metallurgical model of the zinc processing circuit and methods of incorporating zic units recovered from ferrtes into the zinc several alterative , was circuit feed. This work, together with . an economic analysis of the various alternatives documented in the confdential report "10 YEAR MASTER PLAN REPORT" in September 1998 with background metallurgica calculations published in two volumes by DRP personnel entitled ZISMO Case A and B, Zinc Simulation Model, November, 1998.

Centromi Peru is currently working on reinforcment of the river enbankent for remediation of the Huanchan ferrte storage site.


Master Plan (Amount used by FD)

- 32- Doe Run Peru Report to the Mistr of Energy and Mies, 1998

288 AF-030- I DRP Costs Total $32 771



Doe Run Peru has commssioned Fluor Danel and A.D. Zunkel Consultants Inc to complement a DRP team which wil initiate bench scale testing of metals recovery ftom ferrites using both a hydrometallurgical and pyrometallurgical technologies. During this period, an in-situ verification promising- of the ferrte reserves wil be conducted. Assuming favorable outcomes, the most process wil be tested on a Pilot Plant Scale before a decision to build a commercial ferrte processing plant is taken.

Doe Run expects to spend up to US$400 000 on the bench and pilot tests in 1999. If an onle by the end of year economically attractive process is found, a processing plant could be 2002.

STORAGE Piesold Concurrently with the process investigations, Doe Run Peru commissioned Knght Consultores to perform a multi faceted conceptual design which included short term and long term storage of Zinc Ferrtes. The Final Report, Diseno Conceptual de Altemativas para los Depositos de Escoria de Cobre y Plomo, Ferrtas de Zinc, y Basura Domestica was issued in both Englsh and Espafol in June 1998. The study confrms the feasibilty of relocating the Zinc Ferrtes to an environmentally secure storage at the Cochabamba area. The cost of constructing the final storage for ferrtes is estimated at US$2.06 millon or US$2. 93 millon depending on the method of transport. The cost of reclamation, transport, and redeposition of the Zinc Ferrtes the new location has been estimated separately at over US$2 millon. Consideration has also been reclaiming given to deposition of new (current) ferrte production at the new site as well as both material in and relocating the Zinc Ferrtes should it be decided to reprocess a portion of the storage.

Under the advisement of Knght Piesold Consultores, Doe Run Peru concluded early in this work that stabilization of the Zinc Ferrites in-situ is not an attractive option for them.

- 33 - Doe Run Peru Report to the Ministr of Energy and Mies, 1998



This project has the following two main environmental objectives:

- elimination of the current Mantaro River contamination caused by the discharge of raw sewage according to the PAM' s effuent commtment of BOD 5,39 mg/ and TSS ,40 mg/.

- establish environmentally sound handling and final disposal procedures for La Oroya municipal solid wastes.


Sewage Treatment

AM Origial Design Approach

This projec was originy conceived in the P AM accrding to the Aqua Plan Report recommendations to construct two(2) independent biological sewage treatment plants (Chulec an Sudete), with the existing collection sewers connected to a new gravity interceptor with associated sewage lift stations, as required in each area.

The P AM design approach was reevaluated by Doe Run Peru in a study performed by

Sverdrup. The Study report indicates that many aspects have changed over the last three years and many assumptions previously used are no longer valid.

At the time the PAM' s report was prepared by Centromin, the divisions established for two treatment plants, the Chulec treatment plant and the Sudete treatment plant. Doe Run Peru Revised Design Approach The new sewage treatment project recommended for Doe Run Peru is based on two main components, a sewage collection syste~ and one(1) central biological treatment plant. A single sewage treatment plant located at the south end of the La Oroya Smelter takes advantage of the natual terrai for gravity coJlection of sewage without employing excessive pumping or deep sewers, allows sharg of the smelter laboratory facilities, shortens the distance for smelter sewage transmission piping, and places the facilty at a convenient location.

- 34- , '

Doe Run Peru Report to the Mistr of Energy and Mies, 1998

Overal, it is anticipated that 87 lis (2. 0 mgd) of sewage wil be collected and treated. Infuent concentrations of 200 mg/l BOD5 (Biochemical Oxygen Demand) and 200 mg/l TSS (Total Suspended Solids) are expected. Treated effuent wil contain concentrations less than 30 mg/ BOD and 40 mg/ TSS, fulflling the Doe Run Peru AM commttments.

The sewage collection system wil consist of two major branches, one along the Mantaro River ftom Mayupampa to the treatment plant, and the other along the Yauli River ITom Marcavalle to the treatment plant. The gravity pipe sizes range from 8 inches to 24 inches, with a total lineal footae of gravity sewers and force mains of approximately 7 600 including seven pump stations. The Electroandes paricipation has been established on a flow-proportioned basis.

The sewage treatment train includes infuent pumping, mechancal bar screening, grit removal using aerated grt chabers, sequencing batch reactors (SBRs), aerobic sludge digestion, and sludge dewatering using belt filter presses. The SBR was recommended afer a number of treatment alternatives were analyzed by Sverdrup. This is a biological activated sludge process that operates in a batch mode. Instead of constructing separate tans for aeration and clarcation, the SBR uses a single tan for both purposes. The system is flexible, easy to expand, compact, and easy to operate. Doe Run Peru Alternate Regional Design Approach The Ministry of the Presidency is also contemplating capital improvements for municipal sewage collection and treatment in the La Oroya area (Tahal-Ascosesa Study), without distinction between public and private areas.

The focus of the Doe Run Peru project includes improvements to collect and treat sewage ftom the smelter and refiery operations, as well as ffom the supporting Doe Run communities.

A meeting held in May 1998 with the Ministry of the Presidency resulted in a mutual agreement of the sense and synergy of constructing a single, regional collection and treatment system, with potential cost savings ITom the elimination of duplicate sewers and treatment plants.

Doe Run Peru funded an additional prelimnar study prepared by Sverdrup to address a single regional sewage collection system blending the findings ftom the Tahal-Ascosesa and Sverdrup reports. The study area ranged from Paccha to downstream of the smelter on the Mantaro River including La Oroya Antigua, and ftom Curipata to the smelter along the Yauli River.

three separate sewage The Tahal-Ascosesa Report included recommendations to construct using only treatment plants (according to the previous Aqua Plan 1995 Report), but Rotostrainers. This is a physical treatment process that may remove about 30 % of BOD and TSS loadings and wil not attan the effuent quality required according to the Doe Run Peru PAM commtments of30 mg/l BOD and 40 mg/l TSS.

The Sverdrup regional report studied the implementation of regional collection and treatment. Three treatment options were considered in the report:

- 35- Doe Run Peru Report to the Mistr of Energy and Mies, 1998

Option 1 : preliminar treatment with Rotostrainers for the entire regional flow of 230 lis ,(Tahal-

Ascosesa approach) Option 2: biological secondar treatment with SBRs for the entire regional flow

Option 3 : split treatment with Rotostrainers for the public community flows (143 lis), and SBRs

for the Doe Run flow (87 lis). Options 2 and 3 (for the Doe Run Peru flow only) are the only options which comply with the AM efluent quality requirements. Option 3 allows for future expansion and upgrading of the prelimnar treatment train for the public community flow as funding becomes available.

It is the position of Doe Run Peru that the implementation of the regional project is the most appropriate solution ftom environmental, techncal, and economic standpoints. Meetings wil be held between Doe Run Peru and the Federal Governent at the local municipality during the year 1999 to discuss the fidings of the regional report, and to try to find a way of initiating the. regional project.

1998 PROJECT ACTI Doe Run Per performed a comprehensive techncal and economic review of the P AM design

approach which was based on concepts of the Aqua Plan Study in the year 1995. The Project

was executed by Sverdrup, supervised by an engineering team of Doe Run Peru and Fluor Daniel personnel. The following project alternatives were developed:

alterative design to the Aqua Plan approach, based on a single sewage collection and biological treatment system. Alternative designs, with technical and economic considerations

were conceptually detailed in the Sverdrup Report Proposed Municipal Sewerage Improvements (Doe Run Peru ResidentialAreas and Industrial Sanitation Water)- September 02, 1998..

Regional collection and treatment approach. Alternative designs with techncal and economic

considerations were summarized on a preliminary conceptual basis in the Sverdrup Report La Oroya Regional Sewage Collection and Treatment Study - November 1998.


Doe Run Peru Revised Design Approach

The estimated capital cost (without IGV tax) of the revised solution is US$ 1 991 000 for the collection syste~ and US$ 6 088 000 for the treatment plant. Adding estimated costs for engineering and construction (15%) and contingencies (25%), results in a total project cost

US$ 11 311 000. Electroandes would potentially fund US$ 1 100 000 of the total project costs.

A total investment of US$ 3 018 750 ( US$ 2 625 000 + 15% contingencies) was assigned in the P AM.

- 36- Doe Run Peru Report to the Mistr of Energy and Mies, 1998

Project completion is scheduled for the year 2002

Doe Run Peru Alternate Regional Design Approach Two of the three options being currently evaluated comply with the required effuent quality (Option 2 and Option 3), according to P AM agreements. The estimated project costs for those two options are as follows:

Option 2 US$ 25 300 000

Option 3 US$ 20 700 000

An effort to defie the completion date of this alternative has not been attempted.

Garbage Disposal

AM Origial Design Approach This project was originally conceived in the P AMA for domestic solid wastes being generated Aqua Plan report has ftom housing and related facilties belonging to Doe Run Peru only. The recommended the construction of a controlled santary landfil at the current Cochabamba disposal area , designed according to the ''trench method" . Currently, the municipal solid wastes are disposed of at the Cochabamba site, open to the air.

The landfill would be constructed as a multiple module system with, one module attached to another. Each module is of variable length, about 5.0 m wide and 3.0 m high with a lined bottom. Waste would be disposed of in compacted layers of 0. 2 to 0. 3 m, with earth layers between of about 0.4 m thickness.

An offce, control roo~ parking area, biogas stacks, drainage system, and leachate wastewater treatment in septic tanks have been included in project design.

Doe Run Peru Revised Design Approach The PAM design approach was reevaluated by Doe Run Peru in 1998. Knight Piesold

Consultores was contracted to conceptually design alternative deposits for the storage of three of the solid waste products ftom the smelting, refing, and support operations, including the Municipal Solid Wastes.

Doe Run Peru commssioned a comprehensive techncal and economic review conducted by

Knight Piesold in cooperation with a team of Doe Run Peru and Fluor Daniel.

The revised study of municipal solid waste storage at Cochabamba was developed according to two mai options. Project techncal design, econOfnic estimations, conclusions, and recommendations were detailed in the Knght Piesold Report Conceptual Design of

- 37- Doe Run Peru Report to the Mistr of Energy and Mines, 1998

Alternatives for Deposits of Copper Slags, Lead Slags, Zinc Ferrites, and Municipal Solid Wastes - June 1998. The decision on role of the Municipality is stil to be made.

The revised conceptual design of the Municipal Solid Waste landfill has considered a population of 50 000 inabitats (1.35 Kg/capita), including municipal-type wastes which are produced at the smelter, and the surrounding communities of city of La Oroya. The study was developed according to the following two main options:

Deposit of Municipal solid waste, and re-deposited Zinc Ferrtes (trom Huanchan) Deposit of Municipal solid waste, and Zinc Ferrtes in Slurr

The study has been completed to a conceptual design level, for the purpose of providing Doe Run Peru with the information necessar to select a compatible design for the deposit. Sound engineering judgement, and internationally accepted standards have been considered in the design which wi be coordinated with the Peruvian authorities (e.g. Decree Supreme No. 6-STN, dated Januar 9th , 1964).Estimated construction costs, predicted useful lie, and other design implications were also included in Study.

The municipal solid waste deposit wil be enclosed by a 3.0 m high perimeter berm, which wil serve to stabilize the deposit, and control the surface runoff The waste wil be placed in layers and compacted. The deposit wil rise at a 3H: 1 V slope, with an ultimate height of 25.0 m above grade.

permanent cover of low The design provides for a daiy cover for the wastes, as well as a pereabilty compacted soil, drainage gravel, and topsoil. Materials would be obtained trom the imediate area. The deposit has been designed to include a low permeabilty liner, overlain by a leachate collection system. The liner wil combine with the drainage system to channel the antaro effuent trom the deposit to a treatment system, trom where it will be released to the River.

By considering a population served of 50 000 inhabitants, and an average daily rate of waste generation per capita of 1.35 kg/day, the predicted useful life ofthe deposit has been estimated at up to 24 years.

Access roads, backslopes of deposit, as well management of water from surface runoff have been considered in the conceptual design.In order to accommodate the proposed designs in the area of Cochabamba, the Caretera Central will be moved approximately 50 to 80 m. toward the Mantaro River.

The equipment requirements for suiting the operation wil be evaluated and determined in further stages of the design.


- 38- Doe Run Peru Report to the Ministr of Energy and Mies, 1998

The estimated capital cost of the revised solution is US$1.22 millon.

A total investment of US$ 517 500 (= US% 425 000 + 15% Contingencies) was assigned in the PAM.

Project completion is scheduled for the year 2003.


AF-001- RFS-3121 Feasibilty Study 238 161

Estimated Costs December 98 000

Total 243 161

Note: Includes sewage treatment and garbage disposal.

- 39- Doe Run Peru Report to the Ministr of Energy and Mies, 1998



The project objective is to moderne the ambient air quality monitoring equipment in the area of the La Oroya metallurgical complex. Currently, the monitoring is done at five monitoring stations located in a 10 KI radius using six pieces of equipment obtained through an arangement with PUCP-MEM-CMP. Four are old technology PMIO provide by the Catholic University of Lim and one PMIO. This equipment do not comply with some techncal requirements specified by the Monitoring Protocols issued by the Ministry of Energy and Mines. To comply with the legaf requirements of the Ds. Ss. 016-93-EM, 059-93- , the Ministerial Resolution 315-93- EMN and the Monitorig Protocols requirements, this project was developed to implement three monitoring stations which satisfY all the required techncal specifications, along with this fist part of the work, the equipment obtained through the arrangement wil be withdrawn from servce. A data reception center with two computers, a server, and work station are included.


Implement three monitoring stations with state of the ar technology giving on line and real time meaements for the ai qualty of the area of the old and new Oroya adjacent to the smelter operations for the following parameters:

Sulfu Dioxide (SOl)

Hourly Particulate (SPM)

Wind Velocity (WS)

Wind Direction (WD)

Ambient Temperature (AT)

Relative Humidity (RR)

10 Micron samplig of particulate, high volume, 24 hour integration..

10 Micron sampling of pariculate, low volume, hourly integration..

10 Micron sampling of particulate, low volume, instataneous..

- 40- Doe Run Peru Report to the Mistr of Energy and Mies, 1998

It is intended to establish a database on line and to implement an Environmental Information Center. This information wi be useful to establish an adequate strategy to develop the SOz gas emissions and the particulate material projects considered in the P AM within the time trame established by legal requirements with respect to environmenta control.


In this first stage of the project, three stations that meet the United States EP A norm were located in the following monitoring stations:

Hotel Inca area

Workers Union, and

Smelter perimeter area (namely "estacion fundicion

For the fiscal year 1999, the implementation of stations at Huanchim, Casaracra and Cushurupampa is projected together with a closed circuit television system giving a visual register of the smelter emissions.


AFE-022- Equipment Techncal Assistance and 218 268 Facilties.

Total 218 268

This project is not included in the P AM approved by MEM, nevertheless, because this is an investment to comply with the current legal requirements for environmental control, we consider that it should be included as par of the AM related investments.

- 41 - # .

Doe Run Peru Report to the Mistr of Energy and Mies, 1998



The development of the various PAM projects, namely Municipal Sewage System, PAM #16 Industrial Waste Water, PAM #8, Slag Handling Project PAM #12 & 13, Arsenic Trioxide Project PAM #14, and Area Afected by Smelter Fumes PAM #4, demanded that current detailed area survey information was available, preferably in electronic format.


The project objective is to obtain recent survey data of the areas targeted for the P projects. This data wil be used in order to proceed with evaluations of alternative areas and preliary engieering design for the projects as follows:

Municipal Sewage System, PAM #16 - 1:25 000 drawings (Sm. contours) of the La Oroya City including areas such as Curipata, Marcavalle, Chulec, La Oroya Antigua, Refinery, and Smelter areas: to develop the study of the regional municipal sewage collection system, confrm slopes and elevations, and determne pumping stations, etc.

Industrial Waste Water, PAM #8 - 1: 10 000 drawings (1m. contours) of the Refinery and Smelter areas: to develop the Industrial Waste Water collection system, define plant location conf slopes and elevations, determe pumping stations, etc.

Slag Handling Project P AM #12, 13 - 1: 10 000 drawings (1m. contours) of the Huanchan and Area #3 areas: to develop the pt:elimnar storage possibilties, determne total area storage capacity and conceptual designs.

Arsenic Trioxide Project PAM #14 - 1: 10 000 drawings (1m. contours) of the Vado area: to determne area availabilty for designing potential storage ponds, excavation volumes, etc.

Ferrtes Relocation, Domestic Garbage Slag handling Projects PAM #15, 16 12 - 1: 10 000 drawigs of the Cochabamba area: to develop the prelimnary storage possibilties determe real area storage capacity and concep al design.

Area Afected by Smelter Fumes PAM #4: 1:25 000 photography, of the area surrounding La Oroya: to visualy recrd the areas afeced by the smelter emssions.

- 42- Doe Run Peru Report to the Miistry of Energy and Mines, 1998

The electronic fies containing the above data is to be complemented with a complete package of aerial photographs, drawings, and ortho photos of the detail areas mentioned.


The project was completed during 1998. The information has been used significantly to complete reports relating to the projects mentioned above. This information wil continue to be extremely useful when the P AM projects enter the detail design phase.


AF-027 - Aerial Flight, Photos, Etc. 106 349 total 106 349

- 43 - Doe Run Peru Report to the Mimstr of Energy and Mines, 1998


- 44- ""..""''' ------....-.. --- .-.-- -- -..-- .. .. ---

Pb - Closed Circuit Cooling Tower Fite Refinng I..t\ode Casting Waste Water Treatment Plant Acid Plant

2nd Stage Zinc Puification

Zn Roaster

Acid Storage & Slag .1vfanageIIent Chage House Loading

IIII . IlRA DOE RUN PERU FLUOR DANIE LA OROY A SMELTER LAYOUT ""I PER LOCATION OF PROPOSED PROJECTS B'-'- -DATE-Tl- CADD FILl00. "._..--.. ------...... --- ,------..------." . -.------"------... -,-- - ==- --=- .--- -".. -- -.... ----- ::-'.:-''':: -'-






1' DIG D CAD fLE No. IIDATE.Tt.- I 'IU Qt WO - YE C"" 0 IJFU U' - 'r o 18\F

- -.c. -:- - _6 .0 - -.. ,.-- ---'- ..------.-'.. -:. -'"------..--..-,.---- .. - :("- - - - -. .-_-'--""'_'-" --'-----''-""- -- ." ..- -'-. ,-..- - "-- ..-- ..-.--:..--_ . ..- ",.-"'-----_.__""- -....,:::-' :::-'-..:::::::'""----_. '-.--- .''-- --'- -- !-_------"''' ,--- -'=--';.=., .' . - ' .--"- :- -. ---.-:-- ~~~ '--.- ~~~;.;:- :...... -'.--- "'- -.. .--" -.-- ' ....--"..---:- _._ --- ..-- . ~~~ .,,--~~~"--:('" '--/-, .---\ . ' '--;~~~~ - '.""' -''------...: -.. -::-":., , '---.- --- ..".. "- -!;=: ",,=.- ,." -- _. ------, - """'''-.." ,==::- ...-.-, :::::::::::----=="" ~~~~~ -~~~ ;;::::.- ..-- ---=. :::::-~~~ -:=:.

.s '



3'. 9"' -u . ---- . Jr -'- -=_::;:o gf .


-- f' r - " T _no 1'- rr T;1- =o - :i'--

ini iili

-.f/:n: j J. Mo"

.J ""J . '-J.

_..nJr .

"'c ' r .


MING . 1oR1$ ,ASENIC TRIOXIDE M.AAGEMENT .., om SITE FLUO. DAHIl DISPOSN. POND LAYOUT- V mo I! ni fE .. SUAL dol PEU CONTINUOUS CELL METHOD GENERN. ARR.AGEMENT - PL.A 1G1t.- IU II ElI' B 15li II PI (FRJ DMMJlSlS TO 1t1I IE CC US 1I1' CD (f H W. (f 1t II tI 8H PU - ae fO ITIIJE IlIa 1t IF SMfG IEII 1:1000 Ai-101- 255-003 DlR.\I1E."I CI8 8C1F'"'I QIIC C/IO FLE No. 4D1\41J 0- _. "",.,,------'-'- .,', , .------.,.- !:- '-. --.---\,, ...--. "----"------.. '\...---.,.--.-.-,-"--'-----" '"\\- '), ,--../ ------'- '.---- ~~~\\' --'---- ..-.------.,.,---::-:\ - ':::,------"""""-,p.- ..,('\- . '-""-"--'" -'"-) ~~~~~ ,'\:.:--)~~~"'-.\. ..,----,' .....--.. ;::: - ,=-.- , -- -...~~~~~ , -,.--:..';:\ .,..-,.,,;.('-. _.'.."-?:: ",.,--'- -= ---'' ..- :- ''- , ....',,"- /.='~~~ ::-- ,",.' , ",-.,, -'-,,,- ."',__.,':", -' '----'-'-'-""--- - -,-"''~~~ -.---,---_..,,( ))\\.._---,- "- '-'_.-.'--,_-, -- ..----,.-.- ...... --- --.-- - .----'------"-'.'----- .--.... ------:-,-...... , . =-.", .. ..,,-


SOO P.tA, ItWnRMACIO ,7--1.\1 NO SO f"lOS LIE CONS,rtUCClOt' "\l T-- 1-.

L".J!f..J1l.l\l: J1LL-1!.!:.cr:,1 11)

ll- VOL\JMft DE AI IS"(\O) 1M 'f "CEtIMIIEIHO lJ5PON'BLl (m L"1\l- \.1l'" ' 1 III , E".,Ttt.,A(l&' (niiC"::) : '"(1 u...'", WI If( , 1.11. .IEL' !\ , iv \ "U

E.Y, lilJ_ CUpOlll.S llE ur'/El OE. f" l(FF:r.N ) (:.r5fOIl( CAHP.E1EfiA P,...II.EfU"'. 1!A -4 lR00tA. ('l.RF.0Z.ASlE, \i Ril

tlrc:, DE ES(('ft.' P' -.., 0 E51.1(II)U tof r:.U I... . Ef.TiI.IO lI l CABLE (.,PI,'II ' J lff )I UW1E or l' ;(!.IRIA$ ()( DISUK,t PP.OP'JE:: lIUITE Df L.1S POZA3 (iE FE H'"fA?'- or lltlt. If ' "-ISfEtI1E:3 ;J, LINEA FE"REA w,- U.,tJl(:A El SErllOfJ t'El lAlUO OESCErIOEtHE "\C

, i 17$

. 0 -L "t' ..1\1'; :\ Q


MOOlr'C (;ION orl PA.MA .. PPO"rFCTO tt \1f;II:Ao:II)H (..r. ( r::' lit. l luFOPu"\: "1 H F"J"::P."'fl'" l' li l.. fl'l":. lfrl(lo\ I Ir-'JCTIJFf"' FP.IJ..lfuE OEJ- foEc('.rlO':I!lEr-no (, Pf. ll7.:-(i.) F-QFt l.a. EIJPFf.$A l'er ';:OII'5_I(IC m (11( )J(U f', ( Hm. f:'I ;rllt"all r. ar::.)Lf H ::tl If t)(ltiHF:( Df 19' HUANCHAN I'f' rILEu"u( ., f' V:.lF.'.'I(' FO \f"P:'hf.' IO\ I I :-"':Nf0RIAA\:lor lllf' DEPOSITO DE ESCORIAS- PLANTA

$'!:"'1.!, '1'!. Knillht Pi/sold ...... , "IfXU c-::.._ . .., t )'o. h Pft I"1t ,....' t",,';""&/lfV..o:" (tISlJl'I'UUS.Ifl L'''I1'1'fIU l' ""0. '-"'R'rl .,.;. 'CO:-"--h"X (':JII'\.,:.." 'I fl U'!O (ofl 1''1"'." '1, OIl .1( :);n .... nul I -'-0 NrU ,..-- 'L u. If"" "" Fr(l(tY All:".) OI '(11 'O:' O.( ' C4'"! 1. "'OI =(.(.t I/) .. 11' e . ,t(:tI("",,,,'III't "1." 1,.lu-"" "::O- ''!'I....;.VI,IIIO' 1 J1(""!;.o 11..1J(I' r.of-':";"''', I) 10""" '1' ('!l 1'f'.tNT( I \ 0 11: , ':''''..,1 .... ""'r.' "'''' 1:r1(f''.. Err El "!f'.& .. ;Jrn-..IiIII(I) I':CUI"'-.. l'n \r,l"p,) 0"'1 01'1" ,,T""l; . .. ,... .;1,'" ,.,...... ,.- 11 '!.;.o'I",.(, , f1'c+':U::"""III'o(. tfF"" "'-'" (LIO. MY R:: L3T03MA-C I 00

'_U__ U.. ' .:; ",. ,- "- ,.. . ' .--- ,. ~~~~~ . ' hlU I ""u.M""'I'- II I'_ VU.I ""I



Y DE E$ r ABILlDA! - 3950




;'750 f:":;J:;, ,;;'2 ,"M nOD I.




tlSCu tiE N8I ,"ESQ.O c.1OS s... ." Lr H'IfI'O uJuDQ 1ECh I CCfN'I ($CW EL Dt PfII.. N) SlIC CU a 'I4 ClRI.:lJ H: .-OJII sr .. "".CIa 110 'S..Ci , NO" CO'Ufl'o-; (:1CI.w CUo."U..u.8CAC 1). 1r,wl'hl.'K lit\ HC:iH'f fU 0 0( W U'..Alo. fIT PlE5a lA 1f00"'.QI, l.'ttu 1:" U S:EI" M. 'OIS,J1r1I E""US It . PAil CQ1QR:i 'I.. rf AS NlGMA Rfif.SI',I:' 'flfJ s.lI IEGI PO Eu...... -,.-... " ------~~~ - ==- ---' -- :: --.-- .-- '"j:- :: +-- --.- ;. , -.-... '------.. + ,-- '-: . ------.. + '-\ - -. - "'- -'- . -.. --\\- -~~~ ... -'& .--..."- -. -- - - +- "-"''''.--:.~~~. .. ;)---- '... .. --"""'... -.... :;.._.. ': - ' -- -'/-- +~~~- :-.:== -..... --=::-'-:..."-"". ~~~",,=- -- -"" .-'\ ): :\- \' .~~~-+ "" -,,, -- ---. ..\\-- ,-- "\_ ":. ---' +(..:,..-:- -":"' --. (--- . _-, - ':; (-.,-- -==== --- -' .----- .- --'' o- +\H .-If 'l r:i( 'f.- I + 'l S;

:::;dJ f'

. o it

I +

3936. , t PLANT 3930 AREA /J tJ'..,- (IJ) fL.- '/1 925. 9 ' jIIJU

X 3924. 3918.+X fr y,)J

II.. DOE RUN PERU LA OROYA SMELER FLUOR DAH I- .- ' SU do PEU . . TOPOGRAPHICAL LAYOUT c:: I- :n1M I- ''.-11'''' iI""J& J- I- - A1- .. .DAT.E.TIU. "" QWIt - YE C lI Q DIfU II -10 CIK D '1a WD-'I Dil CADD FLE No. \2\ \ -2.. --u ...- \\..--.. - ...- - '\\ .. - -~~~ ------..;.- -- ,--- -..- ~~~~~- - -~~~ ---.. :-.. -..,..-. ,- -~~~",\,, ' -- --,--;;' .- '--- /, - --:.'(/; -' -~~~ - - "-- - - -~~~ . --- .-- .- .':: )'-+. ------, -- ---~~~ .- :- - - ~~~~- ~~~". "-,,--- ::?-- - ::- ~~~'.- ' .- - - -, -~~~::::=~~~ - ---..-==-.: "";:-.-- ""-+ - -- ~~~ . ---. \. - ':".."-- .. - -j -"' /--- --. -- -. " -.. ---.--.... - .: -' ::-'" - ' .- +'-" .\\.- .. : - .-.- - "' -_-, -

. - 8 2. ,,

I, 14. \" 't 1s;\\\ C 1) X j ,( 79

. 311 l\' l//' 7)lff 11 I)); r- 37 . ;,a , 1\ '- X l\ J- ' r' "- ' jr=- v.: ::0 lrr Jrr. r X \\ -d8L))r; f: \3t


:t:;, Wi

:J(j -r 12' r-l .'o \St . X : f-L 3.'1 . ,"13 O,.

X 36'tS. =,IUI.;. :nOO 2 ' F1 .. X It 370P. 9X (.I ,+6cP ' 1\\ ii -- .. IIRA . ZINC FERRITE STUDY I- FLUOR HUN'CHN4 AREA I- SURS dol D.APER TOPOGRAPHICAL LAYOUT I- --_..om...... "" ====fl10""'' I- " - Ai=-- .OATE.YI.E' I 1I00aM.1E.DfID DlflLI.m Olle -8I&lTE-'I DIGO FLE No. \Z \ -.... ------..- ..-- - -.,, ------~~~ ------. ------

"MINRAL i FLUOR DANII SU dol PERU au'1I IIIGEBIlMlI5Htr IF fU IM M) IS!B 1Q DE MICDI1 ..,..-" CD IPIF 'H Ut ". MS -' UE TO JE -- II II.I1I1' 'l1I SWIG EEI :m.:ll

-DATE-TIl' ;'W:.